1. Field of the Invention
This invention relates generally to a modular mold system for the forming of shaped members of similar design but of different dimensions and to a method for using that mold system to produce such shaped members.
More particularly, this invention relates to a modular mold system in which interlocking components are assemblable in different arrangements to form molds of varying dimensions but of similar configuration. The system is particularly adapted to the production of glass fiber reinforced resin products including, for example, containers having an inner and outer shell with insulation placed therebetween.
2. Description of Related Art
It is known in the art to provide molds having a plurality of mold surfaces which are either added to or removed from the mold in order to vary the product size or shape. One such system is shown by U.S. Pat. No. 4,151,976 to Schurman which describes a modular die set for use in blow molding to form containers of similar design but of different dimensions. The die set includes closable die halves made up of die elements arranged so that each element controls only two of the three dimensions of the die cavity. Substitution of different die elements allows the manufacture of products differing in size without requiring complete die sets for each product. The system is particularly adapted for the manufacture of customized blow molded plastic cases.
Adjustable forms are often used in the making of concrete structures such as box culverts and the like and one such system is illustrated by the Crunk et al patent, U.S. Pat. No. 4,123,034. That patent shows a form which includes a pair of wall sections held together with a pair of corner units which are removable from the wall sections. Different sized products are obtained by removing one corner unit and substituting another of a different size. The system as described has no provision for varying the vertical dimension of the mold.
Adjustable mold structures have also been used in packaging systems as is described, for example, in U.S. Pat. No. 4,525,133. That patent shows a packaging system having an outer shell which has a base, a top, and side walls which can be adjusted in dimension to provide an enclosure of desired size. An article to be packaged is placed within the enclosure and a foaming material is injected into the space between the article and the inner walls of the enclosure.
All of the above described mold systems have significant disadvantages were they to be used in the manufacture of glass fiber reinforced resin products of different dimension but of similar design; particularly those products of the type having an inner shell and an outer shell.
SUMMARY OF THE INVENTION
A mold system for use in the manufacture of glass fiber reinforced resin products and the like is made up of interlocking modular components or elements which can be assembled to form molds for products having a similar design but a large range of dimensions. The modular elements are fabricated of metal or other high strength material and include means allowing each of the elements to be rigidly but detachably joined to an adjacent element either of the same or of different configuration. Addition or subtraction of elements allows the dimensions of the mold to be incrementally changed over a wide range. The system is particularly useful in the making of molds for the manufacture of insulated containers in a range of sizes.
Hence, it is an object of this invention to provide a modular system to produce molds which can be incrementally changed in size.
It is another object of this invention to provide molds made of modular elements which can be easily disassembled so as to provide easy removal of the mold from the molded piece.
A specific object of this invention is to provide a method for making molds in a range of incremental sizes and to provide a process for the use of those molds in the manufacture of glass fiber reinforced resin containers.
Other objects and advantages of the invention will become apparent from the following disclosure.